Error 0xC004C003

How to Fix Windows Activation Error 0xC004C003

Fix activation block error 0xC004C003 after hardware changes or clean installs.

Symptoms

  • Windows displays watermark saying it isn't activated
  • Activation settings page shows error 0xC004C003

Common Causes

  • Product key has been blocked by Microsoft licensing servers
  • Significant motherboard or CPU hardware changes

Step-by-Step Solutions

Method 1: Link Microsoft Account with License

Use the Activation Troubleshooter to re-link hardware IDs.

  1. Navigate to Settings > Update & Security > Activation.
  2. Click Troubleshoot.
  3. Choose I changed hardware on this device recently and sign in to your Microsoft Account.

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Frequently Asked Questions

Yes, if you install a different edition of Windows (e.g. Pro instead of Home) than was originally licensed.